English
Related papers

Related papers: Iterations for the Unitary Sign Decomposition and …

200 papers

We study the problem of estimating a rank one signal matrix from an observed matrix generated by corrupting the signal with additive rotationally invariant noise. We develop a new class of approximate message-passing algorithms for this…

Statistics Theory · Mathematics 2025-09-09 Rishabh Dudeja , Songbin Liu , Junjie Ma

An algorithm for computing an analytic function of a matrix $A$ is described. The algorithm is intended for the case where $A$ has some close eigenvalues, and clusters (subsets) of close eigenvalues are separated from each other. This…

Numerical Analysis · Mathematics 2023-12-13 V. G. Kurbatov , I. V. Kurbatova

We propose new primal-dual decomposition algorithms for solving systems of inclusions involving sums of linearly composed maximally monotone operators. The principal innovation in these algorithms is that they are block-iterative in the…

Optimization and Control · Mathematics 2015-11-30 Patrick L. Combettes , Jonathan Eckstein

Obtaining the inverse of a large symmetric positive definite matrix $\mathcal{A}\in\mathbb{R}^{p\times p}$ is a continual challenge across many mathematical disciplines. The computational complexity associated with direct methods can be…

Numerical Analysis · Mathematics 2025-09-03 Ann Paterson , Jennifer Pestana , Victorita Dolean

We use filtrations of the Grassmannian model to produce explicit algebraic formulae for all harmonic maps of finite uniton number from a Riemann surface, and so all harmonic maps from the 2-sphere, to the unitary group for a general class…

Differential Geometry · Mathematics 2010-08-12 Martin Svensson , John C. Wood

In nonadaptive group testing, the main research objective is to design an efficient algorithm to identify a set of up to $t$ positive elements among $n$ samples with as few tests as possible. Disjunct matrices and separable matrices are two…

Combinatorics · Mathematics 2021-10-15 Bingchen Qian , Xin Wang , Gennian Ge

Nonstationary and nonlinear signals are ubiquitous in real life. Their decomposition and analysis is an important topic of research in signal processing. Recently a new technique, called Iterative Filtering, has been developed with the goal…

Numerical Analysis · Mathematics 2019-02-14 Antonio Cicone , Pietro Dell'Acqua

We use the iterative unitary matrix multiply method to calculate the long time behavior of the resonant quantum kicked rotator with a large denominator. The delocalization time is exponentially large. The quantum wave delocalizes through…

Chaotic Dynamics · Physics 2008-01-08 Tao Ma

In this paper, a method via sparse-sparse iteration for computing a sparse incomplete factorization of the inverse of a symmetric positive definite matrix is proposed. The resulting factorized sparse approximate inverse is used as a…

Numerical Analysis · Mathematics 2008-08-03 Davod Khojasteh Salkuyeh , Faezeh Toutounian

We consider the demixing problem of two (or more) high-dimensional vectors from nonlinear observations when the number of such observations is far less than the ambient dimension of the underlying vectors. Specifically, we demonstrate an…

Machine Learning · Statistics 2017-01-25 Mohammadreza Soltani , Chinmay Hegde

We present a novel algorithm for performing the Cartan-Khaneja-Glaser decomposition of unitary matrices in $SU(2^n)$, a critical task for efficient quantum circuit design. Building upon the approach introduced by S\'a Earp and Pachos…

A new scaling and recovering algorithm is proposed for simultaneously computing the matrix $\varphi$-functions that arise in exponential integrator methods for the numerical solution of certain first-order systems of ordinary differential…

Numerical Analysis · Mathematics 2025-09-24 Awad H. Al-Mohy , Xiaobo Liu

In recent years, several algorithms, which approximate matrix decomposition, have been developed. These algorithms are based on metric conservation features for linear spaces of random projection types. We show that an i.i.d sub-Gaussian…

Numerical Analysis · Mathematics 2016-02-11 Yariv Aizenbud , Amir Averbuch

Aitken extrapolation normally applied to convergent fixed point iteration is extended to extrapolate the solution of a divergent iteration. In addition, higher order Aitken extrapolation is introduced that enables successive decomposition…

Numerical Analysis · Mathematics 2013-10-17 Ababu Teklemariam Tiruneh

We consider the problem of low-rank decomposition of incomplete multiway tensors. Since many real-world data lie on an intrinsically low dimensional subspace, tensor low-rank decomposition with missing entries has applications in many data…

Numerical Analysis · Computer Science 2016-08-24 Linxiao Yang , Jun Fang , Hongbin Li , Bing Zeng

We give a number of explicit matrix-algorithms for analysis/synthesis in multi-phase filtering; i.e., the operation on discrete-time signals which allow a separation into frequency-band components, one for each of the ranges of bands, say…

Functional Analysis · Mathematics 2014-12-10 Palle Jorgensen , Myung-Sin Song

In singular value decomposition (SVD) of a complex matrix A, the singular vectors or the eigenvectors of AA{\dag} and A{\dag}A are unique up to complex phase factors. Thus, the two unitary matrices in SVD are unique up to diagonal matrices…

Numerical Analysis · Mathematics 2022-03-24 Chu Ryang Wie

A self-learning algebraic multigrid method for dominant and minimal singular triplets and eigenpairs is described. The method consists of two multilevel phases. In the first, multiplicative phase (setup phase), tentative singular triplets…

Numerical Analysis · Mathematics 2011-02-07 Hans De Sterck

Surface integral equations (SIEs)-based boundary element methods are widely used for analyzing electromagnetic scattering scenarii. However, after discretization of SIEs, the spectrum and eigenvectors of the boundary element matrices are…

Numerical Analysis · Mathematics 2025-05-19 Rui Chen , Adrien Merlini , Francesco P. Andriulli

Many real-world problems rely on finding eigenvalues and eigenvectors of a matrix. The power iteration algorithm is a simple method for determining the largest eigenvalue and associated eigenvector of a general matrix. This algorithm relies…

Numerical Analysis · Mathematics 2021-09-23 Congzhou M Sha , Nikolay V Dokholyan